Abstract
Objective : The objective of this study was to evaluate the clinical value of right ventricular (RV) strain in RV heart disease by cardiac magnetic resonance-based feature tracking (CMR-FT).
Methods : Steady-state free precession images were acquired in 15 subjects : 5 had pulmonary arterial hypertension (PAH) (age : 27.6±14.2 years ; group A), 5 had repaired tetralogy of Fallot without PAH (age : 29.4±10.3 years ; group B), and 5 were normal subjects (age : 32.7±8.6 years ; group C). RV end-diastolic and end-systolic volumes, stroke volume, and ejection fraction (RVEF) were calculated as conventional functional parameters. A developing CMR software was used to obtain the global longitudinal strain (GLS) and strain rate from the 4-chamber view of the heart and global circumferential strain (GCS) and strain rate (GCSR) at the RV mid-cavity from the standard short-axis view of the heart.
Results : Group A had larger and more hypertrophied right ventricles compared to groups B (p<0.05) and C (p<0.05). The RVEF was significantly impaired in group A compared to groups B (p<0.05) and C (p<0.05). The strain values were lower in group A than in groups B (0.01<p<0.05) and C (0.01<p<0.05). The GLS was lower in group B than in group C (p<0.05), while GCS and GCSR had no significant differences between the groups. The strain values correlated with the increasing RV volume and decreasing RVEF in all cases (r=0.41 to 0.52 and r=-0.32 to -0.55, respectively).
Conclusions : The quantification of RV strain values was feasible in most patients by CMR-FT, suggesting that this approach could have clinical relevance in understanding the myocardial mechanics in RV heart disease. The preservation of circumferential strain was important in maintaining the RV function in group B.
